VAN 121: Veterinary Gross Anatomy-II (2+2)

Coronary arteries

CORONARY/CARDIAC ARTERIES

• The coronary arteries are right and left.
• The right coronary artery is small and it arises from the anterior sinus of the aorta.
• It then passes forwards and somewhat downward to the right between the conus arteriosus and the right atrium to the right coronary groove in which it curves around to the right and backwards to anastomose with the left coronary artery at the origin of the right longitudinal groove.
• The left coronary artery is larger and it arises from the left posterior sinus of the aorta, emerges behind the origin of the pulmonary artery and it divides into two branches.
• It gives off in its course dorsal and ventral branches to wall of the aorta, emerges behind the origin of the pulmonary artery and divides into two branches.
• The descending branch passes down the left longitudinal groove towards the apex, supplying branches to both the ventricular walls.
• The circumflex branch runs backwards in the coronary groove, gives off a branch which descends in the intermediate groove, curves to right and descends into the right longitudinal groove. It supplies branches to the atria, ventricles and the origin of the great blood vessels.

• The venous blood from the myocardium is returned largely through two large veins the right and left ascending coronary veins. These accompany the descending branches of the left coronary artery. The right vein is smaller and it joins the left coronary vein to form the great cardiac vein, which joins the vena hemiazygos and opens into the coronary sinus or the right atrium.
• The right coronary artery has no satellite vein. Small venules open directly into the right atrium between the musculi pectinati. ( View image )

Horse and dog

• The right coronary artery is larger than in the ox and it divides into circumflex descending branches.
• The latter passes in the right longitudinal groove.